Approach to reaction mechanism of general anesthetics by biological and physicochemical methods from new viewpoint

（1）研究了挥发性麻醉药、苯二氮卓类、氯胺酮和氟哌利多对Na^+，K^+-ATP酶活性的影响：（1）除芬太尼外，所有麻醉药均呈剂量依赖性抑制Na ^+，K^+-ATP酶活性及其部分反应。Na，K-ATP酶活性及其部分反应的IC_（50）值的大小顺序有一定的规律，具有各麻醉药的特点。麻醉剂对磷酸化中间体（EP）形成的影响在麻醉剂中不同。苯二氮卓抑制EP的形成，而异氟烷和氯胺酮没有。氯胺酮可增加EP对钾离子的敏感性，而异氟醚可降低EP对钾离子的敏感性。这些结果表明，不同种类的麻醉药对Na，K-ATP酶活性的抑制机制是不同的。(2)苯二氮卓类药物通过抑制EP形成后的步骤而抑制Na，K-ATP酶活性，这种抑制作用是部分可逆的。（3）氟哌利多通过降低EP的去磷酸化速率而抑制Na，K-ATP酶活性，这种抑制作用是可逆的。2)为了更好地了解挥发性麻醉药对蛋白质的影响，我们研究了挥发性麻醉药对Na^+，K^+-ATP酶和碱性磷酸酶（ALP）的影响，前者的活性需要脂质，后者的活性不需要脂质。结果表明，脂质并不一定是挥发性麻醉药发挥作用所必需的，而影响挥发性麻醉药作用的因素主要是SDS引起的同工酶一级结构的微小差异和亚基间的微小相互作用或表面结构的改变。

l) We studied the effects of volatile anesthetics, benzodiazepines, ketamine and droperidol on Na^+, K^+-ATPase activity; (1) All of anesthetics except fentanyl inhibited Na, K-ATPase activity and its partial reactions in a dose dependent manner. There were certain patterns, characteristic of each category of the anesthetics, in the order of IC50 values of Na, K-ATPase activity and its partial reactions. Effects of the anesthetics on the phosphointermediate (EP) formation differed among the anesthetics. Benzodiazepine inhibited the EP formation, whereas isoflurane and ketamine did not. The sensitivity of EP to potassium was increased by ketamine but was decreased by isoflurane. These findings suggest that the inhibitory mechanisms of general anesthetics against Na, K-ATPase activity are diverse among the categories of anesthetics. (2) Benzodiazepines inhibited Na, K-ATPase activity by inhibiting the step after EP formation and the inhibition was partialy reversible, and that binding sites of Na, K-ATPase for benzodiazepines were different from those of GABAA receptor.(3)Droperidoi inhibited the ATPase activity of Na, K-ATPase by decreasing the rate of dephosphorylation of EP and that the inhibition was reversible. 2) To better understand the effects of volatile anesthetics on proteins, we studied the effects of volatile anesthetics on Na^+, K^+-ATPase that requires lipids for activity and alkaline phosphatase (ALP) that does not require lipids for activity. The results suggested that lipid is not always necessary for the action of volatile anesthetics, and that the action of volatile anesthetics is influenced by the slight difference of isozymes, for example, primary structure and by the change of slight subunit -subunit interaction or alteration of surface structure caused by SDS.